95977-53-0Relevant academic research and scientific papers
Synthesis and reactivities of enantiomerically pure β hydroxyalkyl and β-aminoalkyl ferrocenyl sulfides
Bernardi, Luca,Bonini, Bianca F.,Comes-Franchini, Mauro,Fochi, Mariafrancesca,Mazzanti, Germana,Ricci, Alfredo,Varchi, Greta
, p. 2776 - 2784 (2002)
Enantiomerically pure β-hydroxyalkyl and β-aminoalkyl ferrocenyl sulfides have been synthesized in good yields from mercaptoferrocene and amino alcohol derivatives. Primary β-aminoalkyl sulfides allowed the synthesis of tetrahydro-1,4-thiazepines containing the ferrocene moiety with good diastereoselectivity and β-iminoalkyl sulfides. Some of these derivatives have successfully been employed as ligands for palladium-catalyzed allylic substitution, with asymmetric induction of up to 99% ee. ( Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002).
waylen apperception HIV reverse transcriptase inhibitors in accordance with the law of the process for the asymmetric synthesis of one-pot synthesis (by machine translation)
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Paragraph 0179; 0180; 0181; 0191; 0192; 0193, (2016/10/07)
The invention relates to a novel one pot method asymmetric synthesis process of a (S)-6-chlorine-4-cylopropyl ethylnen-4-trifluoromethyl-1,4-dihydro-2H-1,3-benzoxazine-2-ketone (Efavirenz) compound, the compound can be used as an reverse transcriptase inhibitor for human immunodeficiency virus (HIV). The invention also relates to a novel aminoalcohol ligand used for the process.
Theoretical and Experimental Optimization of a New Amino Phosphite Ligand Library for Asymmetric Palladium-Catalyzed Allylic Substitution
Magre, Marc,Biosca, Maria,Norrby, Per-Ola,Pàmies, Oscar,Diéguez, Montserrat
, p. 4091 - 4107 (2015/12/26)
A new library of modular amino phosphite ligands obtained in a few synthetic steps from enantiopure amino alcohols has been tested in asymmetric Pd-catalyzed allylic substitution. The modular ligand design is crucial to find highly selective catalysts for each substrate type using a wide range of C-, N-, and O-nucleophiles. A DFT study of the species responsible for the enantiocontrol was used to optimize the ligand structure. By selecting the ligand components, we were able to identify unprecedented catalytic systems that can create new chiral C-C, C-N, and C-O bonds in a variety of substrate types (hindered and unhindered) in high yields and enantioselectivities (ee values up to 99 %). Further studies on the Pd-π-allyl intermediates provided a deep understanding of the effect of ligand structure in the origin of enantioselectivity. Potential applications of the new Pd/amino phosphite catalysts were demonstrated by the practical synthesis of a range of chiral carbocycles by simple tandem reactions, with no loss of enantioselectivity.
CARBONYLAMINO PYRROLOPYRAZOLES, POTENT KINASE INHIBITORS
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Page/Page column 61, (2009/12/28)
Carbonylamino Pyrrolopyrazole compounds of formula I, compositions including these compounds and methods of their use are provided. Preferred compounds of formula I have activity as protein kinase inhibitors, including as inhibitors of PAK4.
Dynamic resolution of N-Boc-2-lithiopiperidine
Coldham, Iain,Raimbault, Sophie,Chovatia, Praful T.,Patel, Jignesh J.,Leonori, Daniele,Sheikh, Nadeem S.,Whittaker, David T. E.
supporting information; experimental part, p. 4174 - 4176 (2009/03/11)
Dynamic thermodynamic resolution of N-Boc-2-lithiopiperidine is possible using a chiral ligand; the two enantiomers of this organolithium can be resolved with selectivities of up to 85: 15 from a selection of 26 chiral diamino-alkoxide ligands screened. The Royal Society of Chemistry.
Optimisation of enantioselectivity for the chiral base-mediated rearrangement of bis-protected meso-4,5-dihydroxycyclohexene oxides: Asymmetric synthesis of 4-deoxyconduritols and conduritol F
De Sousa, Simon E,O'Brien, Peter,Pilgram, Christopher D
, p. 4643 - 4654 (2007/10/03)
A strategy based on diastereoselective epoxidation of a cyclohexene followed by chiral lithium amide-mediated epoxide rearrangement has been used to synthesise an allylic alcohol building block of >95% ee. The key step is the enantioselective rearrangement of a bis-protected meso-4,5-dihydroxycyclohexene oxide. A range of protecting groups and chiral base structures were surveyed in order to find the optimum protocol for high enantioselectivity. Using a tert-butyldimethylsilyloxy protecting group and a norephedrine-derived chiral base, a 93% yield of an allylic alcohol of >95% ee was achieved. To demonstrate the synthetic utility, this allylic alcohol was subsequently transformed into 4-deoxyconduritols and (+)-conduritol F.
Selective Reductions. 37. Asymmetric Reduction of Prochiral Ketones with B-(3-Pinanyl)-9-borabicyclononane
Brown, Herbert C.,Pai, G. Ganesh
, p. 1384 - 1394 (2007/10/02)
The chiral trialkylborane B-(3-pinanyl)-9-borabicyclononane, either with the neat reagents or concentrated solutions, 2 M, reduces a wide range of prochiral carbonyl compounds with good to excellent asymmetric induction.Reduction of simple dialkyl ketones, 2-butanone, 2-octanone, 3-methyl-2-butanone, and 3,3-dimethyl-2-butanone, yields the corresponding alcohols with 43percent, 48percent, 62percent, and 0.7percent asymmetric induction.Acetophenone is reduced to 1-phenylethanol in 85percent ee.The α,β-unsaturated ketones 3-buten-2-one, 1-acetyl-1-cyclohexene, 3-methyl-2-cyclohexenone, and trans-4-phenyl-3-buten-2-one are reduced to the corresponding allylic alcohols with 57percent, 64percent, 11percent, and 97percent asymmetric induction, respecticvely.The α,β-conjugated acetylenic ketones 3-butyn-2-one, 4-methyl-1-pentyn-3-one, and 4-phenyl-3-butyn-2-one underwent a rapid reduction to afford the corresponding propargylic alcohols with 79percent, 99percent, and 91percent enantiomeric purities.The α-haloalkyl aromatic ketones α-chloroacetophenone, α-bromoacetophenone, α-iodoacetophenone, α,p-dibromoacetophenone, α-bromo-p-cyanoacetophenone,α-bromo-2'-acetonaphthone,and α,α,α-trifluoroacetophenone afforded the corresponding halohydrins with 96percent,93percent,93percent,96percent,96percent,90percent,and35percent enantiomeric purities, respectively.The corresponding aliphatic analogue 1-bromo-3-methyl-butanone gave the halohydrin in 66percent ee.The other isomer of this ketone, 3-bromo-3-methyl-2-butanone, failed to undergo reduction.Both the aliphatic and aromatic α-keto esters underwent rapid reduction to give the corresponding α-hydroxy esters with excellentenantiomeric excesses.Thus, methyl, ethyl, isopropyl, and tert-butyl pyruvates afforded the corresponding lactates with 86percent,83percent,78percent, and 92percent ee at 25 deg C,respectively.Lowering the reaction temperature to 0 deg C gave the tert-butyl lactate in 100percent ee.Other aliphatic α-keto esters such as metyl and ethyl 2-oxopentanoates, methyl 3-methyl-2-oxobutanoate, and ethyl 4-methyl-2-oxopentanoate were reduced to the corresponding α-hydroxy esters with 96percent, 96percent, 11percent, and 82percent ee.The methyl, isopropyl, and tert-butyl benzoylformates were reduced to the corresponding mendelic esters with 90percent, 96percent and 100percent ee, respectively.The reduction of the β-keto esters, however, proceeded slowly and ethyl acetoacetate gave the corresponding alcohol with 55percent ee.
